This project uses a variety of epidemiologic techniques in conjunction with collaborating laboratories to investigate the relative role of viruses and genetics in human virus-associated tumors. Emphasis is placed on the intensive study of tumors occurring in unusual situations suggestive of an environmental etiologic factor. Evaluation of the immune response to sepcific candidate oncogenic agents and a search for chromosomal or other genetic markers are performed in an attempt to determine whether genetics affects the response to ubiquitous viruses in the appearance of malignancy. Among the findings in these studies are the following: antibody to HTLV-III was detected in 50 of 75 serum samples collected in Uganda in 1972-73 providing strong evidence that sub-Saharan Africa is the origin of the AIDS virus; analysis of data provided by the Surveillance, Epidemology and End REsults Program (SEER) indicated that the incidence of Burkitt's lymphoma (BL) appears to be increasing in young white males in the United States and that inflammatory breast cancer (IBC) defined clinically may be a distinct entity from pathologically defined IBC; hormone receptor studies support the hypothesis that rapidly progessing breast cancer (RPBC), as determined by patient history, is the same entity as RPBC with objective signs of redness, warmth and edema. A geographic cluster ofnasopharyngeal carcinoma (NPC) and BL, two neoplasms associated with the Epstein-Barr virus (EBV), was identified in a three-county area in Texas; as study of Greenland and Eskimos and Danes demonstrated that early primary infection with EBV correlated with risk of developing NPC.